Dynamic Recovery Solutions Bogus Debt greenville South Carolina

I got a letter demanding $708.41 from this outfit for a debt to Citibank.  I've never had any dealings with Citibank, so I called the number.  The woman I spoke to had my SS number and told me that the debt is from a Citibank Visa opened in 1987.  Forget that these people are calling me about a 27 year old debt, I was only 15 years old in 1987!  What's strange is that they sent this letter shortly after I began actively working on my credit in anticipation of a major purchase.  I honestly believe that this outfit got my information and created a completely fraudulent debt hoping I'd just pay up.  Has anyone else had an experience like this?